The present invention relates generally to file folders, and more particularly to an expandable file folder made from a unitary blank of durable plastic material and having novel construction features providing substantially greater support strength than found in prior expandable file folders.
It is a common practice in commercial business establishments to employ expandable file folders for storing generally flat papers and the like so as to facilitate retention of the papers in desired subject matter categories for ready access. Such file folders are particularly desirable in business offices to enable storage of generally flat papers in upstanding face-to-face relation in selected subject matter files so as to optimally utilize available storage space such as on horizontal shelves and the like. While prior known expandable file folders have proven generally acceptable, they exhibit a number of substantial drawbacks. For example, the known expandable file folders which are of sufficient volumetric capacity to contain a significant number of generally flat papers and the like have, for the most part, exhibited relatively short useful lives when subjected to frequent handling due to their relatively low strength and inability to resist tearing or ripping, particularly in the area of their bottom walls when loaded to near capacity.